As the president took the stage, the protests got louder and closer, as people in multi-coloured clown wigs rushed forward to try to disrupt the event before being led away by security.

When he finally spoke, Ahmadinejad took familiar lines of attack, the unfairness of the UN Security Council, the power of Washington.

But when he turned to the topic of Israel, never mentioned by name, he sparked the diplomatic protest by mainly European countries.

The president blamed the colonial powers for two world wars, and for the establishment of what he described as "a totally racist government in Palestine in compensation for the dire consequences of racism in Europe".

Many stayed

That was enough for some. Britain and France, and some others, had stepped away from the boycott but warned if Ahmadinejad verbally attacked Israel, they'd walk out. And they did.

Suddenly, delegates from at least 30 countries created a long line of protesters snaking towards the main doors as they left the scene in anger.

Yet, for all those that left, there were many that stayed, and many that applauded. To them, this was worth hearing.

In a bullish news conference immediately afterwards, the president criticised those who had walked out, claiming what they had done was take a stand, not against him, but against the goals of the conference.

The timing of the remarks couldn't have been more raw for Israel.

At sundown on Monday, the country marks Holocaust remembrance day, one of the most sombre dates in its calendar.

And many in Israel see the threat from Iran in the same terms as the threat from Hitler's Germany.

Divisions exposed

The roots of this row lie in the original conference on racism held in Durban in South Africa eight years ago.

Day one has been a difficult day for the United Nations [AFP]

Israel and the US walked out then, angry that some at the conference had described Zionism as a racist ideology.

As in Durban, day one in Geneva had been a difficult day for the UN.

This conference was meant to promote tolerance in the fight against racism. Yet intolerance has been a major problem.

A proposal backed by Muslim countries for a defamation of religion clause was dismissed as an attack on free speech, and yet some of those very countries making those criticisms didn't want the president to make his address.

The UN wanted this to be a conference which showed it was united in the fight against racism and injustice.

But on its opening day, all it has done is expose the deep divisions among those present.